This invention relates to an unloading system for a sweeper of the motorized vehicular type having a hopper for receiving debris and means such as a vacuum system for suctioning debris and depositing same in the hopper. The invention is particularly related to an unloading system for expelling debris that has collected within the hopper.
Known street sweepers unload dirt and debris after collection by tipping the hopper, or by raising a false floor inside the hopper while opening a door at the side, or by dumping the debris on the ground through a trapped door in the floor of the hopper. The first two types of unloading systems adversely affect load balance on the sweeper during unloading. The third type of system requires a dedicated area of the undercarriage to be free of other vehicle components, and also results in a ground pile of dirt and debris over which the vehicle drives, which may damage the vehicle tires.
The present invention addresses and solves the above noted and other problems. The invention affords a large capacity street sweeper which is compact and lightweight. A street sweeper in accordance with the present invention offers a high load capacity equal to that of previous large sweepers, yet of significant reduction in weight and dimensional size.
The compact size of the present street sweeper is facilitated by an unloading system comprising a flexible wrapper in the hopper that has a horizontal portion that normally lies upon the bottom of the hopper and an upright portion that normally is held adjacent the front wall of the hopper, with a carriage that progressively transfers the horizontal portion from the bottom to the top of the hopper by way of the upright portion, having the effect of transferring the upright portion from the front to the rear of the hopper. By this means, the wrapper is deformed upon flexure to shrink the cavity and expel debris through an exit door at the rear of the hopper.
A balanced unloading system is afforded without the need for a dedicated undercarriage area free of other components. This facilitates compactness of the sweeper by enabling, for example, the engine and transmission to be mounted below the hopper.